Blacksmithing/Jewelcrafting on my Brewmaster Monk. The most flexible pairing, you can use it for all 3 roles and even use it for secondary stats as well, whereas other professions are generally more rigid and can only provide primary stats.

Which means it works out pretty well as a Brewmaster, as we gem for haste.

Only Mining & Jewelcrafting in this expansion. I was disappointed how common all the ore veins were and how there's way too much supply in the AH of gems and ore, just try to make some money with these professions.

In general I've leveled Tailoring the most to max level (525 or less) on some 4-5 characters already.

Engineering and alchemy. Mostly because when I first made my dk in wotlk I had always wanted an engineer because it was highly praised and alchemy because my buddy told me I could make gold with it. Overall I've been pretty happy though I would like to drop one for BS some day.

Never chose any of them for "buffs" but they're both great. Sure, the only thing engi gives me for raids is a glove enchant and an epic helm of ilvl 476. But it has jeeves and mailbox n shit that's really useful for raiding imo.

Inscription i took cause i've never had it. And i get free, awesome shoulder enchants + i make ALOT of money with it.
I've made around 40k this expansion using inscription, and i haven't farmed ever. I might have bought 10 stacks of herbs once in a while to get materials, and that was enough to earn my cash. Love that profession.
I could never bother with creating glyphs and stuff, i'm too lazy for that, that's why i love the profession, you can make money without burning yourself out! =)